1. Field of the Invention
The present invention relates to a projection headlight for a vehicle, particularly a motor vehicle, including a reflector, a light source mounted in the reflector peak region, at least one stop or mask arranged in front of the reflector and a projection lens arranged in front of the stop or mask. It also relates to an illumination device for a motor vehicle including at least two of these projection headlights, particularly on opposite sides of the vehicle.
2. Prior Art
Because of the only limited available light intensities that they produce headlights for motor vehicles are designed to illuminate a straight section of road of a customary width. The comparatively large light intensities required for visibility purposes are concentrated on the right side of the street at a distance of about 50 m in front of the motor vehicle. During travel of the vehicle around a curve it is appropriate to laterally shift the direction of propagation of the maximum light intensities.
A lighting device for a motor vehicle is described in DT 1 580 740 with rotatably mounted headlights, which provides curve illumination of the curved path of a vehicle travelling around a curve. The entire headlight is rotatable about an at least approximately vertical axis in the frame of the vehicle in this lighting device. The headlight has a connecting drive cooperating with the vehicle steering gear so that the steering gear pivots the headlight in the same direction as, but with a greater angle than, the wheels of the vehicle. The connecting drive for each headlight includes a lever coupled with the steering gear and which performs a pivoting motion about its rotation axis following the steering motion, a fixed element connected to the headlight and a tie rod connecting the fixed element and the lever with spacing from the connecting point from the rotation axis.
In addition, an apparatus including a smaller additional rotationally mounted headlight is known for producing the direction-dependent portion of the illumination.
The problem with devices of the foregoing type is that they require a comparatively large amount of space for their pivoting or rotating parts. Furthermore they have a comparatively large weight and a comparatively large and massive mounting in order to take the comparatively large weight, retaining and drive forces.
Furthermore in order to be able to rotate the entire headlight a gap must be provided between the headlight component group and the covering frame connected with it, which permits rotation of the headlight. This kind of gap is considered to be undesirable in many cases because of its effect on the appearance of the headlight.
Finally also the portions of the light propagated from the rotatable headlight above the permissible light-dark boundary with low beam light, which also may then be rotated into the angular range, in which only certain light intensity values are allowed on account of the opposing traffic, are problematic or troublesome.